1. Field of the Invention
This invention relates to antacid compositions having a prolonged gastric residence time.
2. Technical Review
Classical antacids such as aluminium and magnesium hydroxide gels and co-gels and the new crystalline aluminium magnesium hydroxycarbonates or sulphates such as Hydrotalcite, Almagate and Magaldrate are either rapidly neutralized to water soluble ions or sediment in the fundus of the stomach, and are evacuated into the duodenum by normal peristalsis with subsequent loss of unused drug from its site of action. Consequently they do not neutralize the continuous output of hydrochloric acid by the parietal cells in the human stomach for a prolonged period of time.